Office 365 – Get a sneak peek of what’s coming on Outlook on the Web

End-users accessing their mailbox on Exchange Online with Outlook on the Web (aka Outlook Web Access) will start seeing a toggle to invite them to try the new Outlook on the Web interface.

The toggle will be available on the top right

As administrator you may want to disable this capability; to do so you need to update your OWA mailbox policy to turn off this capability using the following command (NOTE this is not available through the OWA mailbox policy UI on Exchange Control Panel)